Azure VM backups

Which basically does files and folders but in such a way that only the differential changes are sent each time. The question for many IT Pros is how do I recover a complete Azure VM like I can on premises using my traditional disk imaging tools?

The good news is that Azure now has such a services called Azure VM Backup and here’s how to use it.

Best practice is probably to go in and create a new Backup Vault in Azure to ensure you know what storage ‘bucket’ these backups are in. This is because you can back up a lot of different things using Azure services.

It will take a few moments for the new Backup Vault to spin up once you have selected a region for it. Which region you select is important because you can, by default at the moment, only backup VMs from the same region.

Once the new Backup Vault is ready select it, then select Registered Items from the menu across the top. Ensure that the type is set to Azure Virtual Machines and then select the Register link at the bottom of the page.

Place a check in the VM(s) you wish to backup. Then select the check icon in the lower right to save the configuration.

The machine you selected will then be ‘registered’ This means it will have the appropriate configurations made to allow it to be backed up. The VM will need to be running during this process or the registration will fail.

If you now select the Jobs option from the menu you should see the registration process proceeding. The registration should take around 5 minutes but may vary on what type of VM you are backing up.

If you now return to the Registered Items menu option you should see your machine listed as shown above.

With that machine still selected, you will see a number of buttons at the bottom of the page. Select the Protect button to commence a backup of this VM.

Select the items to protect and press the continue arrow in the bottom right of the window.

You’ll then be prompted to create a protection policy. Best policy is to create a new policy, given it a meaningful name and then select the backup frequency.

At this point in the time the most frequently you can backup a VM using this process is once a day.

After you have selected an appropriate Retention Range, select the check to save the settings.

If you wish to do an immediate backup at any time outside the configured schedule, select the Protected Items from the menu at the top of the page.

Ensuring that the desired VM is selected, press the Backup Now button at the bottom of the page.

If you return to the Jobs menu you should see a new job that is “InProgress” as shown above and the Operation is “Backup”.

The VM being backed up of course needs to remain up and accessible during this process.

Even though you can’t schedule backups more frequently than once a day via the browser I’m betting you can via PowerShell and perhaps even use the automated Run Book features of Azure to do this.

The VM you are backing up continues to run as normal and I saw no performance impact occur in this test environment during the process. That may of course vary depending on loads and amount of data to be backed up of course.

To back up a virtual machine, first a point-in-time snapshot of the data is needed. The Azure Backup service initiates the backup job at the scheduled time, and triggers the backup extension to take a snapshot. The backup extension coordinates with the in-guest VSS service to achieve consistency, and invokes the blob snapshot API of the Azure Storage service once consistency has been reached. This is done to get a consistent snapshot of the disks of the virtual machine, without having to shut it down.

After the snapshot has been taken, the data is transferred by the Azure Backup service to the backup vault. The service takes care of identifying and transferring only the blocks that have changed from the last backup – making the backups storage efficient. When the data transfer is completed, the snapshot is removed and a recovery point is created. This recovery point can be seen in the Azure management portal.

So as a I test I used Azure VM Backup to initially backup a Windows 10 machine with Office 2016 installed. That took 37 minutes. Immediately after that backup completed I run another and it took 23 minutes. The Windows 10 system reported about 25 GB of total used space.

Now, what happens when you want to restore? Basically you’ll be restoring the whole machine to a new VM. The current preview of Azure VM Backup doesn’t permit restoring to the original VM, however I’m sure down the track that will become available.

To restore your VM go to the Protected Items options from the menu and ensure the machine you wish to restore is selected.

From the button at the bottom of the page select Restore.

Select a recovery point from the list (this is basically all the backups you have performed). Press the continue arrow in the lower right to continue.

You now need to give the restored VM a name (it can’t be the same as an existing machine so if the original still exists you’ll need to delete it first as source over writing is not yet available).

You’ll also need to select a storage account, virtual network and subnet.

Once you have done that select the check icon in the lower right to commence the restore process.

If you go and check the Jobs option again you should see a restore job in progress as shown above.

For me, after only 8 minutes the restore job completed (that is for a 25GB of data) and if you now look in your Azure Virtual Machines you will see the item your restored, just as it was when you backed it up.

Azure VM Backups are still in preview and there some limits on what features are not available as yet. You’ll find that details in this blog post:

So now you can use Azure to backup up you Azure VMs as you would have typically done on premises using imaging software. Using Azure VM Backup is going to however provide improved ease of use and scalability as well as the ability to more rapidly improve than an existing on premises options.

Azure VM Backup is yet another example of the power the cloud is bringing to traditional infrastructure by making it easier and better.